1. Cotton/synthetic-blend fabrics are easy to wash and dry on the road. If laundry service is a given, our pure cotton wrinkle-free shirts are a great choice for travel too. If you pack enough shirts in your luggage for three days, you have enough for a week. Also, plan to buy a shirt or two at your destination. It's one way to take home a practical souvenir.
2. Choose luggage made of ballistic nylon cloth. These bags are strong, yet light in weight. If you start with a heavy bag, it's all downhill from there.
3. Think about color schemes when you pack. Make sure everything you bring is in the same palette, so it all matches.
4. Think layers. Instead of a single heavy jacket, for example, take light layers that can be added and subtracted according to the weather. For cool climes, take a base layer of merino wool, then a synthetic/cotton-blend shirt, a fleece vest, and then an outer layer shell to stop rain and wind. For cold climates, use a warmer base layer and a thicker fleece with long sleeves.
5. Ship your luggage ahead. It sounds extravagant, but if you're going to a single place where you need a lot of gear (e.g., waders, fly rods, skis, etc.), it's wise to ship it. The parcel services all have good tracking systems, and you'll know where your bag is ahead of time. (I'm doing this for an Alaska trip in August. Who wants to carry waders?)
6. Think ounces. Take the smallest container/amount of toiletries possible, especially if you can replenish at your destination. There's no need to take 16 oz. of shampoo for a one-week trip. Get a couple of small, refillable plastic bottles, and fill them at home before you go.
7. Stay organized. Use nylon bags or large, clear freezer bags to compartmentalize. Put all the socks in one bag, etc. Knowing what you have helps you avoid over-packing.
8. Download a book to your mp3 player.
9. Unless you're a professional photographer, take the smallest digital camera you can. The picture quality will still be excellent.
10. Wear your biggest/heaviest shoes on the plane and pack the lighter ones in your luggage.
11. Don't forget to ask about rental gear before you pack your luggage. Some fishing lodges have everything you need.